Field of the Invention
The invention relates generally to the fields of agriculture, plant breeding, and molecular biology. More specifically, the invention relates to methods and compositions for selectively regulating protein expression in the male reproductive tissue of transgenic plants and uses thereof.
Description of Related Art
Hybrid seed is produced by hybridization or cross-fertilization of closely related plants and can be grown into progeny hybrid plants possessing a desirable combination of traits not possessed by either parent plant. Hybrid plants can display superior agronomic characteristics such as improvement of plant size, yield, nutritional composition, disease resistance, herbicide tolerance, stress tolerance, climatic adaptation, and other desirable traits. Efficient hybrid seed production requires that a plant's own pollen not be permitted to self-fertilize the plant. A major limitation in the production of hybrid seed for many crops is the lack of simple, reliable, and economical methods of making plants male-sterile and incapable of self-fertilization.
In hybrid seed production, pollen production and pollen shed may be prevented in a female parent plant in order to facilitate cross-pollination of the female rather than self-pollination. Such prevention may be achieved by, for example, manual removal of the pollen-containing structures (for example, by manual or mechanical detasseling in maize), use of a genetic means of pollination control (for example, by using cytoplasmic male-sterile or nuclear male-sterile technology), use of a chemical agent, or any combination of these. This can be a labor-intensive and therefore expensive process. In maize, for example, detasseling is typically done in two steps: machine detasseling followed by manual detasseling. Commercial production of hybrid seed using solely chemical gametocides is limited primarily by their general lack of selectivity for gametes and their effect on the other parts of the plant. Thus, methods for improving the efficiency of hybrid seed production are highly desirable.